/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.pinot.segment.local.io.compression;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;
import org.apache.pinot.segment.spi.compression.ChunkDecompressor;


/**
 * Implementation of {@link ChunkDecompressor} using GZIP decompression algorithm.
 */
class GzipDecompressor implements ChunkDecompressor {

  private final Inflater _decompressor;

  public GzipDecompressor() {
    _decompressor = new Inflater();
  }

  @Override
  public int decompress(ByteBuffer compressedInput, ByteBuffer decompressedOutput)
      throws IOException {
    _decompressor.reset();
    _decompressor.setInput(compressedInput);
    try {
      _decompressor.inflate(decompressedOutput);
    } catch (DataFormatException e) {
      throw new IOException(e);
    }
    decompressedOutput.flip();
    return (int) _decompressor.getBytesWritten();
  }

  @Override
  public int decompressedLength(ByteBuffer compressedInput) {
    int offset = compressedInput.limit() - Integer.BYTES;
    return offset > -1 ? compressedInput.getInt(offset) : -1;
  }

  @Override
  public void close()
      throws IOException {
    _decompressor.end();
  }
}
